Traditionally, audience measurement entities determine compositions of audiences exposed to media by monitoring registered panel members and extrapolating their behavior onto a larger, target population of interest. That is, an audience measurement entity enrolls people that consent to being monitored into a panel and collects relatively highly accurate demographic information from those panel members via, for example, in-person, telephonic, and/or online interviews. The audience measurement entity then monitors those panel members to determine media exposure information describing media (e.g., television programs, radio programs, movies, streaming media, etc.) exposed to those panel members. By combining the media exposure information with the demographic information for the panel members, and extrapolating the result to the target population, the audience measurement entity can determine detailed ratings data identifying, for example, targeted demographic markets for different media. However, the composition of a panel may over-represent and/or under-represent different demographic groups of the target population, thereby leading to bias in the resulting ratings data.
More recent techniques employed by audience measurement entities to monitor exposure to Internet accessible media or, more generally, online media attempt to reduce such bias by expanding the available set of monitored individuals to a sample population that may include individuals who are registered panel members, as well as individuals who are not registered panel members. In some such techniques, demographic information for the monitored individuals can be obtained from one or more database proprietors (e.g., social network sites, multi-service sites, online retailer sites, credit services, etc.) with which the individuals subscribe to receive one or more online services. The audience measurement entity may then combine media exposure information with the demographic information obtained for these monitored individuals to determine ratings data for the sample population. Although such a sample population is typically larger than the panels employed by audience measurement entities, the resulting ratings data determined for the sample population may still have demographic statistics exhibiting bias relative to the corresponding demographic statistics of the target population.
Wherever possible, the same reference numbers will be used throughout the drawing(s) and accompanying written description to refer to the same or like parts, elements, etc.